The guys at Frontline Gaming are hosting a tournament in Las Vegas. Since there's a direct flight out of XNA, it wouldn't be too awfully expensive to get to. Plus it should be a blast.
I went ahead and bought a ticket for the 40k GT, but they are having a lot of events. There's a fantasy tournament, doubles for 40k/fantasy, warmachine, and last but not least...... a beerhammer tournament for those of age.
For more details check out www.frontlinegaming.org